In a fluid pressure cylinder which drives a reciprocating rod, that is, a piston rod by hydraulic pressure or pneumatic pressure, when the reciprocating rod is stopped at a stroke end of the reciprocating rod, an impact force is applied to the reciprocating rod and a moving member such as a member to be driven by the reciprocating rod. To decrease the impact force, a buffer such as a resin-made damper, air cushion, hydraulic cushion, shock absorber is used so that the moving member collides with a member on a fixing side through the buffer.
For example, when an electronic component or jig is carried with a reciprocating rod of a pneumatic cylinder, unless any buffer is provided to the pneumatic cylinder, a product to be carried such as the electronic component, namely, a member to be driven receives the impact force at the stroke end of the reciprocating rod. As a result, not only the product to be carried is moved to an unexpected place or damaged or dropped but also a large vibration occurs, thereby shortening a lifetime of the pneumatic cylinder or an electronic-component manufacturing apparatus including the same. To decrease such an impact force at the stroke end, the aforementioned buffer is provided to the pneumatic cylinder. If carrying speed is reduced without providing the buffer in order to prevent the product to be carried from dropping, an operating ratio of the electronic-component manufacturing apparatus drops. If a member for securely fixing the product to be carried to the moving member is used, an entire structure of the apparatus is made large.
The shock absorber as a buffer is often used to stop the product to be carried moving at high speed or to stop movement of a heavy product to be carried. The shock absorber includes one of a type of making a rod protrude from an end portion of a cylindrical case (see Patent Document 1: Japanese Utility Model Laid-Open Publication No. 61-55530).
To use the shock absorber of such a type to absorb the impact force at the stroke end of the reciprocating rod driven by the pneumatic cylinder, the shock absorber is attached to a side face of a cylinder main body while a stopper with which the rod of the shock absorber collides is attached to the reciprocating rod.
FIG. 10 is a perspective view showing a conventional slide table type pneumatic cylinder, which includes a cylinder main body 1 and a reciprocating table 3 mounted reciprocably to a guide rail 2 provided to the body. As shown in FIG. 10, in a pneumatic cylinder in which a reciprocating rod 4 provided to the cylinder main body 1 is connected to the reciprocating table 3 through a linking member 3a so as to drive the reciprocating table 3 by the reciprocating rod 4, shock absorbers 5a and 5b are attached to the cylinder main body 1 through brackets 6a and 6b in order to absorb the impact force at the stroke end of the reciprocating rod 4 or reciprocating table 3, and a stopper 8 with which the rods 7a and 7b of the shock absorbers 5a and 5b collide is attached to the reciprocating table 3.
Also, if the shock absorbers 5a and 5b are attached to the reciprocating table 3, the stopper with which the rods 7a and 7b of the shock absorbers 5a and 5b collide is to be attached to the cylinder main body 1. In any case, the rods 7a and 7b absorb the impact force of the reciprocating table 3 while moving and retracting into cylindrical cases of the shock absorbers 5a and 5b. 
In the shock absorber of such a type, the cylindrical case is filled with fluid such as silicone oil, and a spring or the like for returning, to an original position, the rod moved and retracted at a time of collision is incorporated in the cylindrical case.